Using DNA aptamers and quantum dots for the detection of proteins or other targets

Abstract

The solutions provided here use DNA aptamers and quantum dots for the detection of bacteria, viruses, proteins or other targets. An example of a method described here comprises: providing a complex of DNA complementary strands, one strand being an aptamer, having one strand covalently linked to a quantum dot, and having the other strand linked to a quencher; and contacting the complex of DNA complementary strands with a microorganism or components thereof, under conditions that permit binding of the aptamer with the microorganism or components thereof.

We claim: 
     
       1. A method comprising:
 providing a complex of DNA complementary strands, one strand being an aptamer comprising SEQ ID NO: 1, wherein said strand is covalently linked to a quantum dot and the other strand is linked to a quencher; and 
 contacting said complex of DNA complementary strands with a microorganism or components thereof under conditions that permit binding of said aptamer with said microorganism or components thereof. 
 
     
     
       2. The method of  claim 1 , wherein said complex of DNA complementary strands further comprises at least one metallic particle. 
     
     
       3. The method of  claim 2 , further comprising separating said complex of DNA complementary strands by magnetic capture of one strand, wherein said at least one metallic particle is magnetic. 
     
     
       4. The method of  claim 1 , further comprising immobilizing said complex of DNA complementary strands on a microtiter plate. 
     
     
       5. The method of  claim 1 , further comprising immobilizing said aptamer's target on a microtiter plate. 
     
     
       6. The method of  claim 1 , further comprising detecting whether said aptamer's target is present on an object's surface. 
     
     
       7. A method comprising:
 providing a complex of DNA complementary strands, one strand being an aptamer comprising SEQ ID NO: 1, wherein said strand is covalently linked to a quantum dot and the other strand is linked to a quencher; 
 contacting said complex of DNA complementary strands with a sample; and 
 detecting whether said aptamer's target is present in the sample. 
 
     
     
       8. The method of  claim 7 , wherein said contacting further comprises adding said sample to a microtiter plate pre-coated with said complex of DNA complementary strands. 
     
     
       9. The method of  claim 7 , wherein no blocking step is required. 
     
     
       10. The method of  claim 3 , wherein the other strand of said complex of DNA complementary strands is linked to a non-magnetic metallic particle.